Rotational thrombectomy device

ABSTRACT

A thrombectomy apparatus for breaking up thrombus or other obstructive material in a lumen of a vascular graft or vessel comprising a flexible sheath, and a wire positioned within the flexible sheath wherein the wire and flexible sheath are relatively movable. The wire is substantially sinuous in configuration and assumes a substantially sinuous shape when in the deployed position and assumes a straighter position in the retracted position. The wire is operatively connected to a motor for rotation of the wire to enable peaks of the sinuous wire to contact a wall of the lumen to break up the thrombus or other obstructive material.

[0001] This application is a continuation-in-part of application Ser.No. 09/502,261, filed Feb. 11, 2000, which is a continuation ofapplication Ser. No. 09/122,483, filed Jul. 23, 1998, now U.S. Pat. No.6,090,118, which claims priority from provisional application serial No.60/053,545, filed Jul. 24, 1997, and is a continuation-in-part ofapplication Ser. No. 09/888,149, filed Jun. 22, 2001. The entirecontents of these applications are incorporated herein by reference.

BACKGROUND

[0002] 1. Technical Field

[0003] This application relates to a vascular device and moreparticularly to a rotational thrombectomy device for clearing thrombusfrom dialysis grafts.

[0004] 2. Background of Related Art

[0005] Hemodialysis is a well-known method of simulating renal (kidney)function by circulating blood. The kidneys are organs which function toextract water and urea, mineral salts, toxins, and other waste productsfrom the blood with filtering units called nephrons. From the nephronsthe collected waste is sent to the bladder for excretion. For patientssuffering from chronic renal insufficiency, hemodialysis is life savingbecause it provides a machine to simulate the function of the kidneys,thereby enabling the patients to live independently between dialysistreatments.

[0006] In the hemodialysis procedure, blood is withdrawn from thepatient's body and transported to a dialysis machine, also commonlyreferred to as a kidney machine. In the dialysis machine, toxins andother waste products diffuse through a semi-permeable membrane into adialysis fluid closely matching the chemical composition of the blood.The filtered blood, i.e. with the waste products removed, is thenreturned to the patient's body.

[0007] In one approach, an arteriovenous fistula is created so a highrate of blood flows from the artery into the patient's vein. The bloodis then withdrawn directly from the patient's vein (native vein fistula)providing high rates of blood flow. Since this approach requiresmultiple needle sticks in the vein to withdraw and return the blood, thevein can eventually be damaged beyond usability, blood clots can formand the vein can fail. Once the vein fails, it could no longer be usedfor access and an alternate site must be utilized.

[0008] To avoid the repetitive damage to the vein, dialysis grafts areused. These grafts, typically made of PTFE, are implanted under thepatient's skin, typically in the patient's forearm, and the graft issutured at one end to the vein (venous anastomosis) for outflow and atthe other end to the artery (arterial anastomosis) for inflow. The graftis also typically a loop graft to provide greater access area. Thisgraft, which functions as a shunt creating high blood flow from theartery to the vein, enables access to the patient's blood without havingto directly puncture the vein. That is, the technician sticks the twoneedles into the graft to respectively withdraw and return blood to thepatient, with the inlet on the arterial side for blood requiringfiltration processing and the outlet on the vein side for return ofprocessed blood from the dialysis machine.

[0009] The dialysis graft, while providing an advantageous arrangementfor hemodialysis, may become inoperable after a period of time due tothrombus or clots formed as a result of the high rate of blood flowthrough the graft and repetitive injury at the venous anastomosis.

[0010] There have been various attempts to break up clots and otherobstructing material in the graft. One approach is through injection ofthrombolytic agents such as urokinase or streptokinase. These agents,however, are expensive, require lengthier hospital procedures and createrisks of drug toxicity and bleeding complications as the clots arebroken.

[0011] Other approaches to breaking up clots involve mechanicalthrombectomy devices. For example, U.S. Pat. No. 5,766,191 discloses acage or basket composed of six memory wires that expand to press againstthe inner lumen to conform to the size and shape of the lumen. Thismultiple wire device is expensive and can be traumatic to the graft,possibly causing damage, since as the basket rotates, the graft iscontacted multiple times by the spinning wires. Other risks associatedwith the basket include the possibility of catching onto the graftitself and tearing the graft as well as catching and tearing the sutureat the anastomotic site. Additionally, the basket can become filled withthe a clot which would then require time consuming withdrawal of thebasket, cleaning the basket and reinserting it into the lumen.

[0012] Commonly assigned U.S. Pat. No. 6,090,118, incorporated herein byreference, discloses a wire rotated to create a standing wave tobreak-up or macerate thrombus. The single wire is less traumatic thanthe aforedescribed basket device since it minimizes contact with thegraft wall while still effectively mechanically removing thromboticmaterial.

[0013] This device of the '118 patent is effective in atraumatically andeffectively breaking up blood clots. The present invention likewiseprovides a marked advance over the prior mechanical thrombectomy devicessuch as the baskets. The present invention achieves the same advantagesas the device of the '118 patent, however, it utilizes a wire with asubstantially sinuous configuration to create a wave-like rotationaldevice. Thus, it provides the additional advantages of increasedreliability and consistency in creating the wave pattern since the wavepattern created by the standing wave of the '118 patent will depend moreon the rotational speed and the stiffness of the wire. Additionally, thesinuous configuration enables creation of a wave pattern at a lowerrotational speed.

[0014] Co-pending commonly assigned U.S. patent application Ser. No.09/888,149 incorporated herein by reference, discloses a thrombectomydevice having a double balloon structure. This device advantageouslyreduces the number of individual catheters required to perform thethrombectomy procedure and reduces the number of surgical steps. Thepresent invention therefore provides in one version a double balloondevice with a sinuous wire configuration. The advantages of the doubleballoon thrombectomy device in simplifying the procedure and reducingoperating costs is explained in more detail below in conjunction withthe comparative flow charts of FIGS. 19-20.

SUMMARY

[0015] The present invention advantageously provides a thrombectomyapparatus for breaking up thrombus or other obstructive material in alumen of a vascular graft or vessel comprising a flexible sheath and awire of sinuous configuration positioned within the flexible sheath. Thewire and flexible sheath are relatively movable so the wire assumes asinuous configuration in a deployed configuration and assumes astraighter configuration in a non-deployed configuration. The wire isoperatively connected to a motor for rotation of the wire to enablepeaks of the sinuous wire to contact a wall of the lumen to break up thethrombus or other obstructive material.

[0016] Preferably, the wire is composed of an inner core and an outerlayer. The inner core in one embodiment is formed by at least two wirestwisted together. In a preferred embodiment, the distal portion of theflexible sheath is at an angle to a longitudinal axis of the sheath.

[0017] Preferably, the apparatus further includes a housing having abattery and a motor therein for causing rotation of the wire. In apreferred embodiment, a metal tube is operatively connected to the motorand the wire is connected to the metal tube such that rotation of themetal tube rotates the wire.

[0018] In one embodiment, the apparatus further includes first andsecond balloons and the flexible sheath has first and second lumenswherein the first lumen communicates with the first balloon and thesecond lumen communicates with the second balloon. In one of the doubleballoon embodiments, the first balloon is an angioplasty balloon and thesecond balloon is distal of the first balloon and configured forengaging and pulling an arterial plug into the graft.

[0019] The present invention also provides a thrombectomy apparatuscomprising a flexible tube and a wire positioned within the flexibletube, wherein the wire and flexible tube are relatively slidable so thewire is movable between a substantially straightened position and adeployed position where it assumes a curved configuration. In the curvedconfiguration the wire has a first arcuate region extending in a firstdirection and a second arcuate region spaced longitudinally from thefirst arcuate region extending in a second direction, wherein the firstand second arcuate regions are configured to break up thromboticmaterial as the wire spins.

[0020] Preferably the wire is formed of an inner core of twisted wiresand an outer layer.

[0021] In one embodiment, the apparatus includes an expandable balloonand the flexible tube contains a first lumen to receive the wire and asecond lumen communicating with the balloon for injection of fluid toinflate the balloon.

[0022] The present invention also provides a thrombectomy apparatuscomprising a flexible sheath and a wire rotatably positioned within theflexible sheath composed of at least one wire forming an inner core andat least one wire around the inner core to form an outer layer. The wirehas a first arcuate region extending in a first direction, a secondarcuate region extending in a second direction, and a substantiallylinear region, wherein the first and second arcuate regions break upthrombotic material in a vascular structure as the wire spins.

[0023] The present invention also provides a thrombectomy apparatuscomprising a flexible tube, a wire of non-linear configurationpositioned within the flexible tube and rotatable with respect to theflexible tube, first and second balloons inflatable to expand radiallywith respect to the flexible tube, and a motor for rotating the wire tobreak up the thrombotic material as the wire rotates (spins).

[0024] The present invention also provides a thrombectomy apparatus forperforming a thrombectomy procedure to break up thrombus from a graftfunctioning as a shunt between an artery and a vein. The apparatuscomprises a flexible catheter having a declotting mechanism to break upthrombotic or other obstructive material, a first angioplasty ballooninflatable to expand radially with respect to the flexible tube toperform angioplasty, and a second balloon inflatable to a configurationcapable of pulling vascular material into the graft.

[0025] A method for breaking up thrombotic material from a lumen of avascular graft or vessel is also provided. The method comprises:

[0026] inserting a sheath;

[0027] exposing a rotatable wire with respect to the sheath, the wirehaving a sinuous configuration; and

[0028] rotating the wire so the peaks of the sinuous wire directlycontact the graft wall as the wire spins.

[0029] A method for performing a thrombectomy procedure to break upthrombotic material in a vascular graft which forms a shunt between anartery and a vein is also provided. The method comprises:

[0030] inserting an introducer sheath;

[0031] providing a thrombectomy device having at least one inflatableballoon;

[0032] inserting the thrombectomy device through the introducer sheathand into a vascular graft;

[0033] inflating the at least one balloon to expand the balloon radiallyfrom the thrombectomy device;

[0034] deflating the balloon; and

[0035] actuating the thrombectomy device to break up thrombotic materialfrom the graft.

[0036] The method may further include the step of inflating a secondballoon on the thrombectomy device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Preferred embodiment(s) of the present disclosure are describedherein with reference to the drawings wherein:

[0038]FIG. 1 is an isometric view of the thrombectomy apparatus of thepresent invention showing the flexible sheath (tube) in the extendedposition to cover the rotational wire;

[0039]FIG. 2 is an isometric view similar to FIG. 1 except showing theflexible sheath retracted to expose the rotational wire to enable it toassume its sinuous configuration;

[0040]FIG. 3 is an exploded view of the thrombectomy apparatus of FIG.1;

[0041]FIG. 4 is an enlarged side view of the distal region of therotational wire of FIG. 2;

[0042]FIG. 5 is an enlarged side view of a portion of the wire of FIG. 4showing the inner core and outer layer;

[0043]FIG. 6 is an enlarged side view of the distal tip of the wire ofFIG. 4 showing an atraumatic tip attached to the wire;

[0044]FIG. 7 is side view showing the flexible sheath and knob forsliding the sheath with respect to the rotational wire;

[0045]FIG. 8 is an enlarged side view of the distal end of the flexiblesheath of FIG. 7;

[0046]FIG. 9 is an isometric view of an alternate embodiment of thethrombectomy apparatus of the present invention having an angioplastyballoon and a distal balloon, showing the sheath in the advancedposition to cover the rotational wire and further showing both balloonsin the inflated condition for illustrative purposes;

[0047]FIG. 10 is a cross-sectional view taken along lines 10-10 of FIG.9 showing the lumen configuration of the flexible sheath;

[0048]FIG. 11 is a side view of the flexible sheath and knob for slidingthe sheath with respect to the rotational wire, and showing bothballoons in the inflated condition for illustrative purposes;

[0049]FIG. 12 is an enlarged side view of a distal region of theapparatus of FIG. 9, showing both balloons inflated for illustrativepurposes;

[0050]FIG. 13 is a perspective view showing a looped vascular graftconnecting an artery and vein, a venous access and arterial accesssheath extending into the graft, and the thrombectomy device of FIG. 9inserted through the arterial sheath to access the venous side toperform an angioplasty procedure;

[0051]FIG. 14 illustrates the angioplasty balloon of the thrombectomydevice of FIG. 9 inflated in the vascular graft to perform angioplasty;

[0052]FIG. 15 illustrates the thrombectomy device of FIG. 9 repositionedin the graft for operation of the wire to break up the blood clot;

[0053]FIG. 16 is a perspective view showing the thrombectomy device ofFIG. 9 inserted through the venous access sheath to access the arterialside and the distal balloon inflated adjacent the arterial plug (clot);

[0054]FIG. 17 illustrates movement of the arterial plug into thevascular graft by the distal balloon;

[0055]FIG. 18 illustrates the rotational wire deployed to break up thearterial plug in the vascular graft;

[0056]FIG. 19 is a flow chart showing the steps of the prior art forremoving thrombus from the vascular graft;

[0057]FIG. 20 is a flow chart showing the method steps of the presentinvention for removing thrombus utilizing the apparatus of FIG. 9;

[0058]FIGS. 21 and 22 are perspective and side views, respectively, ofanother alternate embodiment of the thrombectomy apparatus of thepresent invention showing the distal end portion containing shrink wraptubing for receipt of a guidewire; and

[0059]FIG. 22 is a cross-sectional view of the apparatus of FIG. 21showing the guidewire alongside the apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0060] Referring now in detail to the drawings where like referencenumerals identify similar or like components throughout the severalviews, FIGS. 1 and 2 illustrate a first embodiment of the thrombectomyapparatus of the present invention, designated generally by referencenumeral 10.

[0061] Apparatus 10 has a housing 12 composed of housing halves 12 a, 12b, a flexible tube or sheath 40 and a rotational thrombectomy wire 60contained within the flexible sheath 40. A knob 42, extending fromdistal end 14 of housing 12, is attached to the flexible sheath 40 toenable both rotation and sliding movement of the flexible sheath (tube)40 with respect to the wire which is fixed axially. Note that althoughthe flexible sheath 40 is shown as slidable and the wire 60 is fixedaxially, alternatively, the wire can be axially slidable with the sheath40 stationary, or both the wire 60 and sheath 40 can be slidable. In anycase, relative movement of the wire 60 and sheath 40 will enable thewire 60 to be exposed to assume the curved configuration described belowto enable removal of obstructions, such as blood clots, from the lumenof the vascular structure, i.e. the vascular graft or the vessel wall.

[0062] With reference to FIG. 3, details of the internal structure ofthe apparatus 10 will be described. Contained within housing 12 is amotor 22 powered by a battery 24. Actuation button 30 is electricallyconnected to contact terminal 26 b of battery 24 by button wire 28 b;motor 22 is electrically connected to contact terminal 26 a of battery24 by battery wire 28 a. Actuation button 30 is connected to motor 22via wire strip 25 such that depression of button 30, which is accessiblefrom the top portion of housing 12, turns on motor 22 to activate theapparatus. Battery door 33 can be provided to allow access to thebattery 24.

[0063] Wire 60 is operatively connected to motor 22 via support tube 36which is preferably composed of metal. Support tube 36 extends throughopening 53 in Touhy borst 50 and into chuck 38, where a small set screw(not shown) extends through the outer wall of the chuck 38 to engage andcompress the support tube 36 to maintain it in engagement with chuck 38.Belt 29 connects motor 22 to chuck pulley or speed reducing gear 37 todecrease the rotational speed, for example from 10,000 rpm to 3,000 rpm.Shaft 39 of chuck 38 extends through chuck pulley 37. Motor gear 27engages chuck pulley or reducer gear 37. With this connection, whenmotor 22 is energized, the support tube 36 is rotated about itslongitudinal axis, via rotation of chuck 38 driven by gears 27, 37,thereby rotating the wire 60 about its longitudinal axis. This rotationof wire 60 creates at least one vortex that macerates and liquefies thethrombus into small particles within the vascular lumen.

[0064] As noted above, flexible tube (sheath) 40 is slidable withrespect to the housing 12 and wire 60. Flexible tube 40 is alsorotatable. More specifically and with reference to FIGS. 3, 7 and 8,knob 42 has a gripping region 46 and a shaft 48, with a lumen extendingtherethrough. Strain relief 49 is frictionally fit, insert molded orattached by other suitable means to knob 42 and flexible tube 40 isconnected to strain relief 46 (FIG. 3) by insert molding or othersuitable means. With this attachment, sliding movement of knob 42accordingly slides sheath 40 axially and rotation of knob 42 accordinglyrotates sheath 40 about its longitudinal axis. Sliding movement of knob42 exposes rotational wire 60, enabling it to assume its curvedconfiguration; rotation of knob 42 orients the rotational wire 60 due tothe J-shaped distal end of tube (sheath) 40, designated by referencenumeral 47. The proximal end of gripping region 46 contains externalthreads (not shown) for threaded engagement with the distal end ofhousing 12 to lock the sheath 40 in the advanced position to maintaincovering of the wire 60. Extension 48 of knob 42 has external threads(not shown) for threaded engagement within touhy 50 to lock the sheath40 in the retracted position to maintain exposure of the wire.

[0065] The flexible sheath 40 can optionally contain one or more braidedwires embedded in the wall to increase the stiffness. Such braided wireswould preferably extend the length of the sheath 40, terminatingproximal of the angled tip 47.

[0066] Touhy 50, having an extension arm 52, is positioned withinhousing 12 and has a lumen 53 communicating with the lumen of flexiblesheath 40. Fluids, such as imaging dye can be injected through arm 52,flowing through sheath 40 in the space between wire 60 and the innerwall of the sheath 40, and exiting distal opening 41 to flow into thegraft or vessel. This imaging dye provides an indication that fluid flowhas resumed in the graft. Touhy 50 contains a conventional siliconegasket which is compressed when tightened to provide a seal to preventback flow of fluid around the support tube 36. A radiopaque marker canbe provided in the apparatus for imaging to visually locate the positionof the apparatus.

[0067] Turning now to the rotational wire 60 and with particularreference to FIGS. 2 and 4-6, wire 60, in its expanded (deployed)configuration assumes a substantially sinuous configuration. Thissinuous configuration resembles a sine curve.

[0068] As shown, wire 60 has a substantially linear portion extendingthrough most of its length, from proximal region 62, throughintermediate region 64 to distal region 66. At the distal region 66,wire 60 has a sinuous shape in that as shown it has a first arcuateregion 63 facing a first direction (upwardly as viewed in theorientation of FIG. 3) and a second arcuate region 65, spacedlongitudinally from the first arcuate region 63, facing a secondopposite direction (downwardly as viewed in the orientation of FIG. 3).These arcuate regions 63, 65 form “peaks” to contact vascular structureas the wire 60 rotates. The distal tip 69 of wire 60 continues upwardlyas a continuation of the “sine curve” configuration. An atraumatic tip70, preferably composed of rubber, Pebax, or other elastomericmaterials, although other materials are also contemplated, is insertmolded or otherwise attached to the distalmost tip of the wire 60 toprovide the apparatus 10 with an atraumatic distal tip to prevent damageto the graft or vessel wall during manipulation and rotation of the wire60.

[0069] When the sheath 40 is in the advanced position, the curvedregions of the wire 60 are compressed so the wire 60 (including thedistal region 66) is contained in the tube 40 in a substantiallystraight or linear non-deployed configuration. This covering of the wire60 by sheath 40 facilitates insertion through an introducer sheath andmanipulation within the vascular structure. When the flexible sheath 40is retracted by proximal axial movement of knob 42, the distal region 66of thc wire 60 is exposed to enable the wire 60 to return to itsnon-linear sinuous configuration shown in FIG. 2. The wire 60 ispreferably composed of stainless steel which is pre-bent to the curvedconfiguration of FIG. 4 and returns to this position when released fromthe flexible sheath 40.

[0070] In one embodiment, the wire 60 is composed of an inner core 61and outer layer or coil 68. Inner core 61 can be formed by twistingthree wires together in a tight configuration. Outer coil 68 is formedby winding a wire, preferably of larger diameter, to form an openingtherethrough. Note the pitch of the outer coil 68 in region 67 increasesas it is slightly stretched to facilitate attachment of the tip 70. Inmanufacture, the inner core 61 is slid within the opening of outer coil68, and the core 61 and coil 68 are welded together at a proximal anddistal end. This tightly wound outer/inner core structure enablesrotation of the distal end of the wire 60 corresponding to rotation atits proximal end as torque is transmitted to the distal end. Rotation ofthe sinuous wire 60 results in a spiral path to simulate a multiple wirebasket configuration, however with a reduced traumatic affect sincecontact with the vascular structure occurs a fraction of the time.

[0071] Various dimensions of the wire and flexible tube arecontemplated. By way of example only, in one embodiment, where theflexible tube 40 has an outer diameter of about 0.062 inches, the curvedregions of the wire 60 would extend from the longitudinal axis adistance of about 0.188 inches and the radius of curvature at region 65would be about 0.376 inches in a wire having an overall diameter(combined outer coil and inner core) of about 0.035 inches. As can beappreciated, these dimensions are provided by way of example as otherdimensions are also contemplated.

[0072] In use, the thrombectomy apparatus 10 is inserted into the graft(or vessel) through an access sheath and located via imaging. Once inthe graft, the flexible sheath 40 of apparatus 100 can be rotated so theJ-tip 47 is oriented to the desired position. Once in the desiredposition, the flexible sheath 40 is retracted, and button 30 isdepressed to actuate motor 22 thereby causing support tube 36 and wire60 to rotate about their longitudinal axis, causing the arcuate regions63. 65 to directly contact and break up the thrombotic material insidethe lumen of the graft (or vessel). Note that the location of the accesssheaths for introducing the thrombectomy apparatus 10 can be appreciatedby the illustration in FIG. 13 which shows use of apparatus 100discussed below. Although the procedural steps differ between apparatus10 and apparatus 100, the introducer sheath location could be the same.The introducer sheaths can optionally have side ports for aspirating thesmall macerated particles.

[0073] Alternate Embodiment—Thrombectomy Device with Balloon(s)

[0074]FIG. 9 illustrates an alternative embodiment of the thrombectomyapparatus of the present invention, designated generally by referencenumeral 100. Thrombectomy apparatus 100 is similar to apparatus 10 ofFIGS. 1-8, except for the provision of two inflatable balloons and twolumens in the catheter, each communicating with one of the balloons toallow passage of inflation fluid. Thus, the apparatus has a housing 112,a flexible sheath (tube) 140 and a rotational wire contained withinsheath 140 identical in configuration and function to wire 60 of theFIG. 1. Knob 144 is rotatable to orient J-tip 146 and slides tube 140 touncover the rotational wire in the same manner as knob 42 of FIG. 1.Note that FIGS. 9, 11 and 12 show both balloons inflated forillustrative purposes since in the preferred use of the apparatus asdiscussed in detail below, only one balloon would be inflated at a time.

[0075] The flexible sheath 140 of apparatus 100 has a lumen 110,illustratively circular in cross-section, for receiving the rotationalwire 160, and first and second lumens 113, 114, each communicating witha balloon, for inflating the balloon. More specifically, first lumen 113communicates with angioplasty balloon 120, which is preferably somewhatelliptical shape, and second lumen 114 communicates with balloon 124,which is preferably substantially spherical in shape. Inlet ports 130,132, communicate with lumens 113, 114, respectively, to inflate therespective balloons 120, 124.

[0076] The double balloon thrombectomy apparatus 100 reduces theprocedural steps for thrombus removal and can be appreciated bycomparison of the flow charts of FIGS. 19 and 20. In the prior art, twoindependent balloon catheters plus a mechanical thrombectomy device arerequired to perform a thrombectomy procedure; with the presentinvention, only one device, apparatus 100, is required.

[0077] More specifically and with reference first to the anatomicaldrawing of FIG. 13, a vascular graft G functions as a shunt between theartery A and vein V. Graft G is sutured to the artery at arterialanastomosis site 210 and is sutured to the vein at venous anastomosissite 212. A venous access sheath 218 is inserted on the arterial sideand extends through the graft G to access the venous side; an arterialaccess sheath 214 is inserted in the venous side and extends through thegraft G to access the arterial side.

[0078] Describing first the prior art method, which is not shown, andwith reference to the flow chart of FIG. 19, an angioplasty ballooncatheter is inserted through the venous access sheath and advanced tothe venous anastomosis site, where the angioplasty balloon is inflatedto treat the stenosis, i.e. expand the lumen by removing plaque. Thenthe angioplasty balloon is deflated and the balloon catheter is removedthrough the venous access sheath. Next a thrombectomy device is insertedthrough the venous access sheath into the graft. The thrombectomy deviceis then actuated to clear the thrombus and other obstructive material inthe graft. The broken particles can then optionally be removed bysuction with the thrombectomy device in place or after removal of thedevice form the graft.

[0079] Next, after removal of the thrombectomy device from the sheath,an arterial access sheath is inserted to access the arterial side. Aballoon catheter, containing an expandable balloon such as a “Fogartyballoon”, is inserted through the sheath and advanced past the arterialanastomosis so the tip is past the arterial plug (clot) adjacent theanastomosis site. The balloon, preferably composed of Latex, althoughother materials are contemplated, is inflated, and the balloon catheteris moved proximally to pull the arterial plug into the graft. Theballoon is then deflated and the balloon catheter is removed througharterial access sheath. The thrombectomy device is then inserted througharterial access sheath into the graft, and actuated to break up thearterial plug. The particles can optionally be removed from the graft bysuction with the thrombectomy in place or removed from the sheath. Thethrombectomy device is withdrawn from the arterial access sheath tocomplete the thrombectomy procedure.

[0080] As can be appreciated, this prior art method requires two ballooncatheters in addition to the thrombectomy device. Further, this priorart method is time consuming since it requires four instrumentinsertions and removals: angioplasty balloon catheter, thrombectomydevice, balloon catheter, and thrombectomy device.

[0081] With the thrombectomy device of FIG. 9 of the present invention,these numerous catheter insertions and removals are avoided. As depictedin the flow chart of FIG. 20, and as can be appreciated by the methoddrawings of FIGS. 13-18, fewer steps are required.

[0082] After the venous access sheath 218 is inserted, the thrombectomydevice 100 which contains an angioplasty balloon 120 is inserted throughthe sheath (FIG. 13) so tip 146 extends past plaque P. Angioplastyballoon 120 is inflated via lumen 113 as shown in FIG. 14 to remove andcompress the plaque P to open the lumen. The angioplasty balloon 120 isthen deflated and the apparatus 100 is moved proximally so therotational thrombectomy wire 160 is in the region of the graft G at theblood clot C as depicted in FIG. 15. The apparatus 100 is then activatedto spin the sinuous wire 160 to break up the thrombus and otherobstructive material. Suction can then optionally be applied either withthe apparatus 100 in place, with the particles being removed through thegap between the flexible sheath 140 and the introducer sheath 218, orthe apparatus 100 can be removed and suction applied through the sheath218.

[0083] After breaking up the blood clot, apparatus 100 is removed fromvenous access sheath 218 and inserted through arterial access sheath214. The apparatus 100 is inserted so the tip extends slightly beyondthe arterial anastomotic site 210, past the arterial plug (clot) D, andthe spherical distal balloon 124 on apparatus 100 is inflated (FIG. 16).The apparatus 100 is then pulled proximally so that balloon 124 pullsthe arterial plug D into the graft G (FIG. 17). The thrombectomyapparatus 100 can then be actuated to rotate wire 160 to break up theclot D (FIG. 18) and other obstructive material, and optionally thebroken particles can be removed by suction as described above. Thethrombectomy apparatus 100 is then removed through arterial accesssheath 214, completing the thrombectomy procedure.

[0084] It is also contemplated that as an alternative to the doubleballoon thrombectomy device, a single balloon device can be provided.This device could contain either angioplasty balloon 120 or balloon 124.If only balloon 120 is provided, although the procedure would stillrequire a separate balloon catheter to remove the arterial plug, itwould still advantageously eliminate the step and expense of a separateangioplasty catheter. Alternatively, if the single balloon devicecontained only balloon 124, although the procedure would require aseparate angioplasty balloon catheter, it would still advantageouslyeliminate the step and expense of a separate balloon catheter forpulling the arterial plug into the graft.

[0085] It should also be appreciated that the double balloon concept tofacilitate and expedite the surgical thrombectomy procedure can beutilized with other thrombectomy devices. For example, mechanicalthrombectomy devices utilizing rotating wire baskets, fluid jet(hydrodynamic) devices applying high pressure fluid, devices utilizingbrushes having bristles to scrape the clot and devices with rotatingimpellers can be modified to incorporate one or more balloons, i.e. anangioplasty and/or distal balloon to perform an angioplasty procedureand/or pull an arterial plug into the graft.

[0086] In the alternate embodiment of the thrombectomy apparatus inFIGS. 21-23, apparatus 200 (only the distal portion is shown) isidentical to apparatus 100 except for shrink-wrap tubing 202 around adistal portion of the apparatus 100 to form an opening or lumen 204 fora guidewire. A guidewire 206 would be inserted through the arterialaccess sheath and past the stenosis (arterial clot). The guidewire 206would then be threaded through the lumen 204 formed between tubing 202and the outer surface 209 of flexible sheath 212 (which containsinflation lumens 216 and lumen 218 for the rotational wire). Guidewire206 enters at entrance port 216 and exits through exit port 214, toextend along the length of flexible sheath 212. In this manner, thisrapid exchange feature would allow the apparatus 200 to be more easilyadvanced past the arterial plug or stenosis as it is threaded over theguidewire.

[0087] As an alternative to the shrink wrap tubing forming the guidewirelumen, the catheter could be provided with an additional lumen formedtherein, extending a short distance at the distal end portion, toaccommodate the guidewire.

[0088] While the above description contains many specifics, thosespecifics should not be construed as limitations on the scope of thedisclosure, but merely as exemplifications of preferred embodimentsthereof. Those skilled in the art will envision many other possiblevariations that are within the scope and spirit of the disclosure asdefined by the claims appended hereto.

What is claimed is:
 1. A thrombectomy apparatus for breaking up thrombusor other obstructive material in a lumen of a vascular graft or vessel,the apparatus comprising a flexible sheath and a wire positioned withinthe flexible sheath, the wire and flexible sheath being relativelymovable so the wire has a first configuration and a second deployedconfiguration, the wire being sinuous in configuration and assuming itssinuous configuration when in the deployed configuration and having astraighter configuration in the first configuration, the wire beingoperatively connected to a motor for rotation of the wire to enablepeaks of the sinuous wire to contact a wall of the lumen to break up thethrombus or other obstructive material.
 2. The thrombectomy apparatus ofclaim 1, wherein the wire is composed of an inner core and an outercoil.
 3. The thrombectomy apparatus of claim 2, wherein the inner coreis formed by at least two wires twisted together.
 4. The thrombectomyapparatus of claim 3, wherein in manufacture the inner core is slidwithin the outer layer and welded together at proximal and distal ends.5. The thrombectomy apparatus of claim 1, wherein the wire is composedof a plurality of wires twisted together.
 6. The thrombectomy apparatusof claim 1, further comprising a soft blunt tip affixed to a distal endof the wire.
 7. The thrombectomy apparatus of claim 6, wherein a distalportion of the flexible sheath is at an angle to a longitudinal axis ofthe sheath.
 8. The thrombectomy apparatus of claim 1, further comprisinga housing, the wire extending from the housing, the housing furtherincluding a battery and a motor for causing rotation of the wire.
 9. Thethrombectomy apparatus of claim 8, further comprising a metal tubeoperatively connected to the motor, the wire connected to the metal tubesuch that rotation of the metal tube rotates the wire.
 10. Thethrombectomy apparatus of claim 1, further comprising first and secondballoons, and the flexible sheath has first and second lumens, the firstlumen communicating with the first balloon and the second lumencommunicating with the second balloon.
 11. The thrombectomy apparatus ofclaim 10, wherein the first balloon is an angioplasty balloon and thesecond balloon is configured for engaging and pulling an arterial plug,wherein the first balloon is proximal of the second balloon.
 12. Thethrombectomy apparatus of claim 1, further comprising an angioplastyballoon expandable radially with respect to the flexible sheath.
 13. Thethrombectomy apparatus of claim 1, further comprising an inflatableballoon for engaging and pulling an arterial plug into the lumen of thegraft, the balloon expandable radially with respect to the flexiblesheath.
 14. A thrombectomy apparatus comprising a flexible sheath and arotatable wire positioned within the flexible sheath, the wire andflexible sheath being relatively slidable so the wire is movable betweena substantially straightened position and a deployed position where itassumes a curved configuration, in the curved configuration the wirehaving a first arcuate region extending in a first direction and asecond arcuate region spaced longitudinally from the first arcuateregion and extending in a second direction, the first and second arcuateregions configured to break up thrombotic material as the wire spins.15. A thrombectomy apparatus of claim 14, wherein the wire is formed ofan inner core of twisted wires and an outer coil.
 16. The thrombectomyapparatus of claim 15, further comprising an expandable balloon andwherein the sheath contains a first lumen to receive the wire and asecond lumen communicating with the balloon for injection of fluid toinflate the balloon.
 17. A thrombectomy apparatus comprising a flexiblesheath and a wire rotatably positioned within the flexible sheath, thewire composed of at least one wire forming an inner core and at leastone wire around the inner core to form an outer layer, the wire having afirst arcuate region extending in a first direction, a second arcuateregion extending in a second direction, and a substantially linearregion, the first and second arcuate regions breaking up thromboticmaterial in a vascular structure as the wire spins.
 18. A thrombectomyapparatus comprising a flexible tube, a wire having a non-linearconfiguration and positioned within the flexible tube and rotatable withrespect to the flexible tube, the wire having a non-linearconfiguration, first and second balloons inflatable to expand radiallywith respect to the flexible tube, and a motor for rotating the wire tobreak up thrombotic material as the wire rotates about its axis.
 19. Athrombectomy apparatus for performing a thrombectomy procedure to breakup thrombus from a graft functioning as a shunt between an artery and avein, the apparatus comprising a flexible catheter having a declottingmechanism to break up thrombotic material or other obstructive material,a first angioplasty balloon inflatable to expand radially with respectto the flexible catheter to perform an angioplasty procedure, and asecond balloon inflatable to a configuration capable of pulling vascularmaterial into the graft.
 20. A method for breaking up the thromboticmaterial from a lumen of a vascular graft or vessel comprising;inserting a sheath; exposing a rotatable wire with respect to thesheath, the wire having a sinuous configuration; and rotating the wireso peaks of the sinuous wire directly contact the graft wall as the wirespins.
 21. A method for performing a thrombectomy procedure to break upthrombotic material in a vascular graft which forms a shunt between anartery and a vein, the method comprising: inserting an introducersheath; providing a thrombectomy device having at least one inflatableballoon; inserting the thrombectomy device through the introducer sheathand into a vascular lumen; inflating the at least one balloon to expandthe balloon radially from the thrombectomy device; deflating theballoon; and actuating the thrombectomy device to break up thromboticmaterial from the graft.
 22. The method of claim 21, wherein the step ofactuating the thrombectomy device comprises the step of exposing arotatable wire and rotating the wire.
 23. The method of claim 22,wherein the thrombectomy device includes a second balloon, and themethod includes the step of inflating the second balloon.